Roll type glue spreaders, surface coaters, and the like



March 1, 1960 R, s, BLACK Erm.-

ROLL TYPE GLUE SPREADERS, SURFACE COATERS. AND THE LIKE Filed Sept. 7,1956 InvenTors: 'abe VT 5. Back 8f LTcxmfz 5.C roU roll.

United States latent O 11 claims., (cl. 11s-244) This invention relatesto that general type of glue spreader, or surface coater, disclosed inLetters Patent of the United States No. 2,326,429, issued AugustlO, 1943on the application of lohn E. Black and Robert S. Black, but as willhereinafter appear, certain features of novelty herein disclosed are notlimited in their application to devices of the general type of thatearlier patent and are yof more general application. However, forpurposes of illustration of `the present improvements we willhereinafter make reference to that earlier patent. In` so doing,however, we do not intend to limit the protection to be lafforded by thepresent application and the Letters Patent `to be issued thereon, exceptas we may do so in the claims to follow.

Generally speaking the presently disclosed device infcludes two mainrolls" which are journalled one above 4the other in a common verticalplane and with their respective axes extending horizontally, `togetherwith means to apply to the surfaces of such rolls the desired adhesivein liquid form. When both surfaces of a sheet areV tobe coated suchadhesive is applied by maintaining both of the rolls coated with theadhesive; when only one surface of the sheet is to be coated only one ofthe rolls is maintained coated with the adhesive, generally the upperThe sheet is passed horizontally between the two rolls, for whichpurpose such rolls are setto a clearance between them proper to pass thethicknessof the sheet then being coated. Usually a resilient device isprovided in the roll supporting assembly to permit one of lthe rolls toshift slightly away from the other under resilient force,

to take care of slight inequalities in sheet thickness `and for otherpurposes; but the roll supporting assembly also includes means to enablethe operator to accurately predetermine and maintain the normalseparation between the rolls at that value which will properly receiveand `treat the thickness or" sheets being treated. Such general 'typesof device are disclosed in that earlier patent,g'and are also disclosedin the devices herein disclosed. f

' In order to provide on the main roll or rolls a film of adhesive to beapplied to the sheet surface or surfaces suitable means are provided'to`produce this function. r

One such means comprises a doctor roll for eachrmain roll, suitablyjournalledwith its axis parallel to that` of its main roll, and insubstantial horizontal alignment therewith. Each such doctor roll thusprovides in conjunction 'with its main roll a V-shaped trough or crotch,and suit- V able end plates `are provided in contact with theends of thepair of rolls at the location of such trough or crotch to enclose theends thereof, and thus provide a pocket within which the adhesive isretained and from which itis fed to the surface of the main roll. Byadjusting such The thickness of such film of adhesive (usualiCe andacting to shift the axis of the doctor roll towards' of away from theaxis of the main roll. Such devices are also shown in the aforesaidLetters PatentrNo. 2,326,429,

and means to effect such adjustments are also disclosed in the presentapplication.

In order to `better `control the thickness of the film of adhesive whichis applied to the surface ofthe sheet being coated, and to ensure a moreuniform thickness of such film over the entire surface being coated., ithas been found desirable to provide the surfaces of the main rolls withrather fine encircling grooves, eithercircular and self-contained, or ofspiral form. These grooves, when provided, arev of s mall dimensionsboth as to pitchbetween successive grooves, and as to their depth. Suchgrooves may be of the order of 22 per inch axially of the roll, anddepth of the order of 0.025 inch. Sometimes fsuch grooves are of V-shapewith one side wall of the V extending radially of the roll, or normal toits axis', and the other side wall of such V of suticient angle to theplane normal to the rolls axis to provide the desired cross-section ofthe groove. Sometimes such grooves are formed Vso that neither wall ofthe groove lies normal to the rolls axis but both of the walls of thegroove lie within planes or surfaces (conical in form) which are Vatacute angles to the axis of the roll. In such case an undercut form ofgroove is produced. Both forms of such grooved main rolls are shownV inLetters Patent of the United States No. 2,343,363, issued March 7, 1944on the application of John E. Black and Robert S. Black.

In order to permit slight deformations of the surface of the main rollas it exertspressure against the surface of the sheet being coated theperipheral surface of the main roll is generally formed of yieldableandresilient material such as rubber, neop-rene or like materials. Rollsof such type are also shown in the aforesaid Letters Patent of theUnited States, and said Letters Patent also shows such surfaced rolls asprovided with grooves of both of the forms previously referred toherein. It is here noted, however, that the surfacing of rubber, neoprene, or other yieldable material as disclosed in that earlier patentis homogeneous through its entire thickness from its outer perimeter tothe supporting tube or hub on which such surface of yieldable materialis mounted. Thus the hardness and characteristics of such surfacecoating are substantially uniform for the entire radial dimension ofsuch surfacing. It is here noted, also, that such surface coating issubjected to wear during usage, thus changing its overall diameter andthe 'contour-sof the grooves. `To meet this condition it is desirable touse, for such surface coating, a yieldable material of considerabletoughness combined with that degree of resiliency needed -to meet theoperating conditions. Those operating conditions include both the needof allowing for slight inequalities in the thicknesses `of the sheets atdifferent locationsas such sheets ride between the two main rolls, aswell as permitting the grooves lto deform under surface pressure exertedradially against the main rolls by the Asheet being treated so as to-expel the desired amount of adhesive onto each uni-t area ofthe surfacebeing coated.

Thus, in that earlier patent it was disclosed that yieldable `materialof the general hardness of the order of 210 toV '60 on th scale of theShore durometer was considered satisfactoryl l Now, evidently thedeformation of the surface of the surfacing is formed, the radialdimension ofthatsurfacing, the lform and size of the grooves, theirspacing,anc l sheet thickness at different areas thereof willnecessarily produce corresponding variations in the deformation of themain rolls surface since the parts are under opposing pressureconditions. These deformations of lthe main roll-s surface are of twokinds; First, they include deformations ofthe ridges between the'successive grooves of the roll surface, and Second, they include bodilyshift of the ridges radially inwards towards the axis of rotavtion. (Thelatter deformations can be produced only at 'the expense of the formerdeformations, since the de- "forming pressure is exerted radially inwardfrom the elemental areas of roll rsurface which are in cont-act withLthe surface of the sheet being treated, and these elemental areas whichfirst receive the pressure Vfrom the sheet beingtreated are theouteredges of the ridges between the grooves. When the entire thicknessradially ofthe yieldable surfacing is homogeneous, as disclosed in thatearlier patent, is it evident that by .far the greater portion of theyield produced by the pressure of lthe sheet being treated will be takenup by the ridges between the grooves, since the body .of such ridgestperunit radial dimension) is fmuch smaller than the body of thesup-.porting non-ridged section .of the surfacing of lthe yield- .ablematerial. in other words, the pressure exerted per .square inch sectionof the ridges is much vgreater than .thepressure exerted per squarelinch section of that portion of material radially inwards from theridges. Thus, for. a given pressure exerted against the perimeter of the.so-formedroll, most of the deformation will occur with- .in the radialdimensions of vthe ridges between ,the grooves, and only a very smalldeformation radially will `occur inthat 'body o-f yieldable materiallocated-radially .inwards from the ridges themselves.

LVariations `'in the amounts of deformations of the .ridges willnecessarily result in variations of amount .of adhesiveexpelled overcorresponding areas of thev main rolls, :and with corresponding`variations in the thickness .of .the l-m of adhesivefplanted on thevarious elemental areas of the sheet surface being coated. Thus, it nowbecomes evident that variations in the sheet thickness vmust necessarilyresult in variations in the thicknessof y.the film planted'on thesurface of the sheet at corre ...sponding locations. Thus a seriousdisadvantage in .the .uniformity of .treatment of the sheets surfaceoccurs, and the uniformity of application of the adhesive 4to .all areasof the sheets `surface is destroyed. .Since itis ya desirable Quality ofthe coating Vmachine to ensure .substantial uniformity of application ofthetadhesive to-'all lareas of .the sheetssurface it is .desirable tomakempro 7^#visionto .meet and counteractthe underlying .structural'features ofthe main rolls which features have hereto ffore .producedthis objectionable condition. It Yis Y the ,prime Vobject of the present.invention :to provide inathe vmain rolls :further kstructural featureswhich willfensure y'attainment of this desirable result.

'-'We :have provided andshall disclose ,herein .a main rollconstructionin tsuchgroll .type glue .spreaders and @surfacecoatersAwherein `we provide Ya1rather .thin :surface .of tough, somewhat hard.resilient 4yieldable material, fcapableof resisting the wearnecessarilyattendant :on .the -nperationjiofgsuch devices, .and provided lwith.ag-groomed :dged surface .capable of ensuring ,the expulsion 'of tithedesired l.amount of adhesiveby .deformationxofisuch .zridges, .togetherwith .a supporting ybase of rather fsoft, preferably'spongy material ofyicldable material .of Ielaslfilature, Ksuch v.soft .base being such *asto Y yield :sufstcientlyzto take care of .mostof .the inequalities .inthick- .guess .of fthesheet .being treated, :with .a yminimum varia:fion-:in `the ideformationsof .the.;ridges at the v4surface .oflthezrroll. ilhus we .have comhinedgthe .function :of exfgilsn fa:desired tamount .of adhesive hy slight Aradial .fde'formati'on fof .therolls surface ridges, .togethervwith provision rto .take fcare 'of theinequalities. yin :sheet thickfbyf=votying mums -of yield of .thesoft-ibase.

so .embodying .the features :of the Vpresent invention, the{uppermne-.hlf Lof such .tgure being in vertical section, ,andintermediatesections -o'f the roll beingleft .out `to The functionaloperation of the foregoing combination maybe likened to an elastic unitformed of arather stiff spring and a softer spring in series so that thedefoirning force is exerted through both sections. Such an arrangementwhen subjected to a deforming force will produce a slight deformation ofthe `stiff spring section, and a much greater deformation of the softerspring section, so that slight variations of deforming force will actprincipally to produce changes vin the deformation of the softersection, and comparatively insignificant changes in the deformation ofthe stiff section. By way of illustration only, and not as a matter oflimitation we have successfully used main rolls 'having surface sectionsof tough, resilient long wearing material, of a hardness ofsubstantially 65 point durometer on the Shore A scale, such materialconveniently being rubber or neoprene, together with a base section,preferablyV very spongy and of a softness of substantially 12-15 pointdurometergon the Shore A, scale. With such a combination, and using asurface section of substantially inch radial dimension, and a basesection of substantially l inch radial dimension all of the desirablequalities hereinbefore explained have been attained, and theobjectionable qualities eliminated. The base section may conveniently bevformed of sponge` rubber, neoprene, or other resilient material. Takingaccount of the greater radial dimension of the soft .base `and itsgreater softness specification, and themuch smaller radialV dimensionvof the hard outer section and vits much greater hardness of lessersoftness, itis evident that by far the greater amount of the deformationchanges produced by slight inequalitles in the thickness of the sheetbeing coated will .be taken up by the Vbase section, Vand substantiallywithout change inthe deformations of the ridges between the grooves ofthe contacting surface. vThus a substantially .uniform l'rate ofdelivery of the adhesive to the surface being treated will'be ensured,ensuring substantially equal amounts of vadhesive to all equal areas ofthe treated surface, notwithstanding inequalities in the .thickness ofthe Sheet being treated, or other like irregularities.

Other objects and uses of the invention will appear `from la detaileddescription of the same, which consists .in the features of constructionand combinations of parts hereinafter described and claimed.

In the drawing:

Figure .1 shows, schematically, a surface. coater em .bodying the.features of the present invention, and in "cluding two main rolls invertical alignment, together with corresponding doctor rolls located 4insubstantial horizontalalignment with their main rolls, together with.spring vyieldablemeans urging the upper main roll .down-y Wardly, `and:horizontally :adjustable doctor rolls which may be :adjusted withrespect to their companion main irolls .to'providexthe desired smallclearances betweenthe main and doctor rolls, .and also .including meansto adjust the elevationofsthe lower main roll to provide for accomvrmodation ofsheetsfof various thicknesses, but with slight .verticaladjustability lof .the `upper main roll corresponds .ing to 'sheets of'.dcviationfrom intended thicknesses, etc.; .figur-e2 .shows .alongitudinal view of a main roll l the grooves :zare not undercut .butare `provided with vplanar fsurfacesion one -side of each ridge, suchplanar surfaces lbeingnormal tothe axis of .rotation of the rroll. .In,Figure l .the upper :and lower .main rolls .are .shown at 11 and 12,respectively, and the companion doctor rolls are shown at 13 and 14,respectively. The upper main roll is shown schematically as providedwith the upwardly extending vertical stem 15 carrying one of thejournals for such roll, shown at 16. The other journal and stem are notIshown inFigure l as they` have been cut away in such figure. A spring17 urges the stem 15 downwardly to produce a pressure of the uppermainroll against the sheet 18 being coated, such sheet travellingtowards the left as shown in Figure 1. The journal 19 is shown for oneend of the lower main roll, being connected to a stem 20. The journalfor the near endof such roll is not shown in Figure 1 as it too has beencut away in such figure, and this is also true of thecorrespondingdownwardly extending stem. By adjusting the stems for .thelower rollfs journals the elevation of such lower roll may be adjustedto meet requirements of various specified thicknesses of sheet stockbeing fed between the wo rolls. To effect such adjustments such lowerstem 201 is shown as being threaded to receive an adjusting screwelement. The two doctor rolls are shown as provided with the journals 21and 22, respectively, each such journal being provided with acorresponding horizontally extending stern 23 or 24 Vas the case may be,it being understood that the near journals and stems have been cut awayin Figure` l. These stems 23 and 24 are shown as being threaded toreceive adjusting elements whereby the doctor rolls may be adjustedtowards and away from their companion main rolls to adjust theclearances 25 and 26 between such doctor rolls and their companion mainrolls. Pockets or crotches are thus provided between the doctor and mainrolls, the ends whereof are closed by plates (not shown) so thatadhesive or other liquid material to be applied to the surfaces of thesheet 18 may be carried by the main rolls to the sheet areas beingtreated, the amount or thickness of the film of such adhesive which willbe planted on the surface of the sheet being thus adjustable by thesetting of the doctor rolls. Such arrangements are disclosed in theaforesaid Letters Patent No. 2,326,429, and here shown for purposes ofillustration only, and as showing the relationship of various featuresof the present invention to the functions and operations which areproduced by the complete machine.

Reference is now had to Figure 2 which shows the detailed constructionof one of the main rolls.` It comprises the two end blocks 27 and 28which are provided with the outwardly extending shaft extensions 29 and30, respectively. These shaft extensions are provided with suitablejournal receiving sections 31 and 32, which receive journals such asthose shown at 16 and 19 in Figure l. Blocks 33 and 34 are secured tothe blocks 27 and 28, preferably by seating such blocks onto the innerend portions of the blocks 27 and 28, respectively, and welding theparts together as indicated in Figure 2. The blocks 33 and 34 areconveniently shouldered as shown at 35 and 36 to receive the ends of atube 37 which constitutes the unyieldable element on which the yieldableelements of the roll are mounted. Con veniently the proximate portionsof the tube ends and the blocks 33 and 34 are kerfed as shown at 38 and39 to enable the tube ends to be welded to said blocks, thus providing astrong rigid support for the yieldable ele ments of the roll.

The yieldable section of the roll is tubular in form, comprising theinner rather thin tubular sheet 40, of metal or rather hard rubber orthe like, on which is directly mounted the cylindrical inner softresilient yieldable section 41. Onto this soft inner section 41 there ismounted the outer harder cylindrical section 42 also of yieldable,resilient material, such as rubber, neoprene, or other like material.The roll illustrated in Figure 2 has an outside diameter ofsubstantially A11% inches. The thickness of the outer section 42 thenhas a value of substantially t inch, and the thickness Yof the innersection a value f substantially l inch. These two sections may becemented or otherwise secured together, or the outer sectionmay beslightly expanded in diameter and then slipped onto the innei` section,and then allowed to contract into firm engagement with such inner'section.` In operation the two sections are in sufficiently firnengagement, the one with the other that they must rotate at all timesexactly as a unit'. Preferablythe outer perimeters of the blocks 33 and34 are carried outwardly as flanges 43 and 44, respective.-l ly tooverlie and protect the ends of the yieldable `sections; but it isnoted` that `such flanges are of slightly smaller external or outsidediameters than the outer surfaces of the section 42 so that suchanges'43 and 44 do not come in contact with 13 or 14 or shall not comeinto direct engagement with the surface of the sheet being coated incase such sheet should inadvertently over run the end or ends of theroll.

Reference to Figures 3 and 4 will show two alternative forms of groovingand ridging the outer surface of the yieldable section 42. Duc to thefact that the grooves shown in Figures 3 and 4 have a depth of only theorder of 0.025 inch they cannot be conveniently shown in the section ofFigure 2, but they are indicated by the annular lining of the lower,unsectioned one-half of Figure 2. In the form shown in Figure 3 thegrooves 45 are shown as being undercut at their left-hand faces 46 byforming such faces at an acute angle to a plane normal to the axis ofroll rotation; and the right-hand faces 47 are then formed at a greateracute angle to such plane normal to the axis of rotation, the outerencircling annularqsurface 48 lying within the perimeter of the roll.The surfaces 48 are those which cornerinto direct contact with the sheetsurfaces being treated. Upon exerting directly inward radial pressureagainst such outer surfaces 48 the ridges which they terminatewill belaterally deformed as shown by the dotted lines in Figure 3, thusexpelling some of the adhesive contained in the groove since the volumeof such groove will thereby be reduced. In the modified form of ygrooveshown in Figure 4 the left-hand faces 46a of the ridges are formed inplanes normal to the axis of rotation instead of at acute angles as inthe former showing. However, generally speaking both forms of groove andridge are subject to the same laws of operation and analysis.

Now the hardness (or lack of softness) of .the outer section 42 ascompared to the lsection 41 is such that when a deforming force has beenexerted on the outer surfaces 48 to deform the ridges at any extent,inward pressure is also being developed against the soft yinner section41. Thus such section will also yield inwardly, so that a lessdeformation of the ridges will occur than would be the case with aninner section of material substantially of the same hardness (or lack ofsoftness) as the outer section 42. Accordingly, less adhesive will beexpelled from the adjacent grooves than would be the case with a harderinner section. The hardnesses of the two sections can be made such inrelation to each other that when a certain pressure or force has beendeveloped against the outer ridge surfaces `48 with correspondingexpulsion of desired amount of adhesive, further force developed againstsuch ridges will cause inward deformation of the inner section as fastas the outer surface 48 is forced inward, so that a limit is thenreached as to the amount of adhesive which may be expelled from thegroove. Thus, excessive pressures developed against the surfaces 48 willnot thereafter change Ithe amount of adhesive which will be expelled.This function is directly related to the fact that the outer section 42is formed of much harder yieldable and resilient material than the innersection 41.

We claim:

l. In a roll type surface coater, the combination of a pair of mainrolls, means to journal said rolls for rotation on parallelA .axes andwith the proximate surface portions of the rolls separated from Veachother a distanceto accommodate the thickness oa sheet of stock to besurface coated, means to rotate `said rolls in opposite directions, atleast one of .such main rolls comprising a stiff cylindrical base, atubular section Aof soft, yieldable, resilient material of substantiallyuniform radial thickness of the order of one inch mountedon saidcylindrical base, and a tubular' section of tough, resilient material ofsubstantially .uniform radial thickness of the orderof inch mounted onsaid soft yieldable resilient .material section, together with means tosupply a controlled thickness lm of coating material to the surface ofsaid. main roll the radial dimension of said tubularsection of toughresilient material being not over substantially one-half the radialdimension of said .tubular section of soft, yieldable resilientmaterial.

2. Means :as defined in claim 1, wherein, said soft, yieldable,resilient material section is composed of rubberlike material.

-3. Means Xas defined in claim l, wherein said soit, yieldable,resilient material section is of spongy formation.

V4. `Means as dened in claim 3, wherein said soft, yieldable, resilientspongy material section is composed of rubb er-like material.

5. Means as defined in claim l, wherein lsaid tough,

.resilient material'seotion is composed of rubber-Elternaterial.

6. Means as defined lin claim `l, wherein said soft, yieldable,resilient material section has -a hardness of sub.-

stantially 12.-. 15 point durometer on `the .Shore A .scale of hardness.y

7. Meansas dened in claim 1, wherein said'rtough, resilient :materialsection has a hardness of substantially '6 5 point durometer on theShore A scale of hardness.. 8. yMeans as defined Ain claim 7, whereinsaid soft, Vy:ieldab.le, resilient material section has a hardness.ofsubstantially 12- 15 point durorneter on the Shore A scaleofrhardness.

9. :In .a `roll type surface coater, the. combination of a pair of mainrolls, means to journal said rolls lfor rotation on parallel axes andwith -the proximate surface portions of the rolls separated from eachother a distance to accommodate the thickness of a sheet of stock to. besurface coated, means to rotate said rolls in opposite directions, atleast one of such main rolls comprising la stiff cylindrical base, atubular section of soft, yieldable, resilient mate-rial of substantiallyuniform radial thickness mounted on said cylindrical base, and a tubularsection ojf tough, resilient material of substantially uniormradialthickness mounted on VVsaid soft yieldable resilient material section,together with means to supply a controlled :thickness iilrn of coatingmaterial to the surafce of said main roll, and a series of circularVgrooves in the surface of said tough, resilient tubular section, .withcircular ridges between said grooves, the outer edge portions of suchridges comprising sheet stock surface engaging areas of said tough,resilient tubular section the radial dimension of said tubular sectionof tough, resilient material including the circular ridges thereof beingnot over substantially one-half the radial `dimension of said tubularsection of soft, yieldable resilient material.`

l0. .Means as defined in claim 9, wherein the opposite faces .of each.ridge are Aformed at different angles with respect `to the axis ofrotation of said main roll.

All. vMeans as delined in claim 10, wherein the ldepths of said groovesradially are substantially one fifteenth of theradial thickness of `saidtough, resilient tubular section.

'References Cited in the le of this patent UNITED STATES PATENTS l,"Black et al. Mar. 7, 1944

